Hi,
I'm not young in Linux. I made many-many installations with many mistakes. So, I know how to .....
I tried to install ARCH on /dev/hdb3. I have also installed on the same HD the debian/sarge on /dev/hdb1 with the swap on /dev/hdb2.
I think I followed all the steps. I didn't get any error message. I rebooted my system.
The stange is that there aren't the known directories ( /boot, /usr, .... ). I dont know what I installed.
I supposed I missed something. But What?

PS. Sorry for my english. Salute from north greece. The summer is here.

What happens when you boot? you just say you don't have the typical directories, but not what you do have.

I'm not sure if this is the issue or not, but I've had a lot of trouble with getting the boot loader installed, both times I've installed Arch I had to install grub from a liveCD.

Did you follow their most explicit instruction? - Make sure you select done after each stage.

Arch installer allows you to do the steps not necesarily in the correct order, make sure you indeed installed packages etc and set /dev/hdb3 as the / mount point